Excelsior knife



Nov. 27, 1951 F. H. PHILLIPS -2,576,190

EXCELSIOR KNIFE Filed July 19, 1949 2 SHEETS-SHEET 1 l V i I H i 4 J r/f I I l 0 0 IE. 1 I 5 o o I l //vv/vr0z FRANK ll. fl/ll-l/FS waflwzw F.H. PHILLIPS EXCEILSIOR KNIFE Not 327, 1951 Filed July 19, 1949 PatentedNov. 27, 1951 UNITED STATES PATENT OFFICE This invention relates to aknife for use in cutting excelsior. Specifically, the knife of thisinvention is secured in an excelsior cutting machine and is reciprocatedover a wood bolt to remove strips of excelsior from the bolt on eachadvancement of the knife over the same.

An object of the invention is to provide an improved knife for anexcelsior machine which will cut ridges of varying height in a bolt toprovide for more satisfactory and uniform cutting of excelsior from thebolt.

Another object of the invention is to provide a knife for an excelsiorcutting machine constructed such that it will produce ridges ofdifferent height on a bolt to provide a degree of compressibility to thesurface engaged by the cutting plate of the machine and thereby permitof easier adjustment of the cutting depth of the knife, and provide acertain amount of leeway in setting the knife so that it will outcorrectly at every stroke.

Another object of the invention is to provide a knife for an excelsiorcutting machine in which the knife is formed with a series of parallelgrooves having round bottoms to provide a reinforcement to the shoulderof the teeth, and to provide for a feather-edge cutting by the cuttingedge of the grooves to permit more satisfactory operation of the knifeon a greater variety of woods, and particularly soft woods.

Further objects and advantages will become apparent from the drawingsand the following description.

In the drawings:

Figure 1 is an elevational view illustrating the operational position ofa knife relative to a bolt.

Figure 2 is a plan view of the cutting plate holding the knife.

Figure 3 is an end view of the cutting plate.

Figure 4 is a plan view of the knife for the excelsior cutting machine.

Figure 5 is an enlarged plan view of a portion of the knife of Figure 4to more clearly illustrate the construction of the grooves in the faceof the knife.

Figure 6 is a cross-sectional view taken along line 6-6 of Figure 5.

Figure 7 is a cross-sectional view taken along line 1-| of Figure 5.

Figure 8 is a cross-sectional view taken along line 8-8 of Figure 4.

Figure 9 is a cross-sectional view of a bolt i1lustrating the surfacethereon after being worked upon by the knife of this invention.

In Figure 1 there is illustrated a cutting plate ill of an excelsiorcutting machine that carries the knife II. The knife II has grooves 112in theshank 13 thereof through which are placed bolts M for securing theknife II to the tool-head IE on the cutting plate ID.

The cutting plate H3 is provided with the guides 6 that guide thereciprocating movement of the cutting plate in the excelsior cuttingmachine.

' A wood bolt 20 is positioned against the cutting plate In and is urgedagainst the same, and advanced toward the same, by any conventionalapparatus well known in this art.

As the cutting plate reciprocating over the bolt 20, grooves 25 providedin the knife H remove wood shreds from the surface of the bolt, in themanner well known in the art.

The knife I l of this invention is provided with the series of parallelgrooves 25 in one face of the knife. The working end of the knife isprovided with a bevelled surface 26, as shown in Figure 6, whereby thegrooves 25 in the face of the knife form a series of teeth 21 thatremove wood shreds from a bolt to produce excelsiors.

The grooves 25 in the knife are arranged in groups 250, that are eachseparated from the other by a second groove, 25!) that is deeper thanthe grooves 25a. The bottoms 28d and 28b of the grooves 25a and 251) areall rounded, as shown in Figure 8, thereby providing radiused shoulders30 at each vertical edge of the respective grooves which therebystrengthen the lands 3| between all of the grooves.

In Figure 5 it will be noted that the grooves 25a and 25b of differentdepth, produce teeth 32 of different length. Also, the round bottom ofthe grooves 25a and 25b provide radiused shoulders 35 between each ofthe grooves and the teeth 32 thereby strengthening the teeth 32.

When the knife I l works upon a bolt, such as the bolt 20, a ridgedsurface is produced on the working face 40 of the bolt. The deep grooves251) produce high ridges 4012 on the bolt while the shallower grooves25a. produce ridges 40a slightly less in height than the ridges 4%.

As shown in Figure 3, the ridges 401) are those that are primarilyengaged by the cutting plate [0, and since these ridges are few innumber, and since the wood itself has a degree of resiliency, there willbe provided a degree of resiliency between the bolt 20 and the cuttingplate Ill. This resiliency between the bolt 20 and the cutting plate istaken advantage of at the time the knife is set for the correct depth ofout. Since the bolt 20 is urged against the cutting plate ID by suitablepressure rolls, the resiliency of the several high ridges 40b willpermit a certain degree of leeway in setting the knife H for its depthof cut. This is of particular advantage since the prior methods ofcutting all grooves to the same depth presented ridges of all the sameheight to the cutting plate, so that the relatively rigid surfaceprovided by the ridges of all the sam height made it extremely difficultto set a knife at'the correct desired depth, this being particularlytrue when producing wood Wool.

Since the high ridges 401)- on the bolt when" by the various depthgrooves will not be precisely in alignment with one another across theknife, a more uniform cutting of the bolt is obtained, andsofter woodscan be used.

By using a knife of the construction described herein, the useful lifeof the knife is increased since the teeth are greatly strengthened andthus breakage of the teeth is largely eliminated, such breakagerequiring costly re-grinding of the cutting edge and excessive removalof useful tool material, which greatly reduces the tool life.

Having thus fully described my invention. what I claim as new and desireto secure by Letters Patent is:

1. A knife for an excelsior cutting machine having a bevelled edgeforming a cutting edge and having a plurality of parallel grooves in itsface that cooperate with the bevelled cutting edge to form a pluralityof cutting teeth, said grooves including grooves of deeper depth thanthe other of said grooves, said grooves of deeper depth being spacedperiodically across the face of the knife.

2. A knife for an excelsior cutting machine having a bevelled edgeforming a cutting edge and having a plurality of parallel grooves in itsface that cooperate with the bevelled cutting edge 't'o'form a pluralityof cutting teeth, said grooves being arranged in groups in which all ofthe grooves inthe respective groups are of the same depth and in whichthe groups are separated from one another by a groove of deeper depthREFERENCES, CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Number V 7 Ward .1 May 31, 1898

